Signal system



c. G. s UlTs 2,100,881

SIGNAL SYSTEM Nov. 30, 193 7.

Filed March l2. 1936 Direct/'on of Fff/c I T'wvento: C hauncey G. Suits,

H is Attorney.

Patented Nov. 30, 1937 UNITED STATES SIGNAL SYSTEM Chauncey G. Suits, Schenectady, N. Y., alsignor `to General Electric Company. a corporation of New York Application March 12, 1936, Serial No. 68,405

13 Claims.

My invention relates to railway block signal systems and one o f its 'objects is to provide ein improved electrically operated signal systeiii, whereby the signals may be more satisfactorily and reliably controlled than has been possible heretofore.

In the usual form of signal system, means are provided whereby the signal or signals at the entrance of a block which is occupied by a vehicle are caused to indicate danger,`and the signal or signals at the entrance of the block at the rear of the vehicle are caused' to indicate caution, the latter indication being frequently dependent upon the presence of a following vehicle in the second block to the rear.

The value of a signal system depends, of course, upon the reliability of the system under all circumstances and under all possible types of failure. For example, when a lamp burns out the indicacation given must .be in the progressively safe direction. Any type of failure which causes two lamps to be lighted simultaneously in the same block is considered bad because of the psychological effect upon the engineer. It should be understoodthat in railway practice a very dangerous signal is given to the engineer when no lamp in a block is lighted since the engineer interprets this condition to mean that the signal system is out of order and may fail, therefore, to indicate a hazardous situation. It is, therefore, an object of my invention to provide an improved railway signal system which satisfies the above safety requirements.

It is a further object of my invention to provide 5 a railway signal control system which may deenergize a signal lamp by supplying a current thereto which is of like magnitude but opposite phase to the current normally flowing the lamp.

It is a still further object of my invention to provide an improved type of saturable reactor which increases the reliability of performance o a railway signal system.

The novel features which I believe to be char-4 I have represented at l one track of a two trackv railway system.4 This track is divided into blocks A, B, C, etc. in accordance with common practice, the rails of the different blocks being electrically im insulated from each other as is indicated at the through points 2 and 8. At l, 5, and 6 I have indicated the signaling equipments which are associated with each of the blocks A, B, and C, respectively. These equipments are all identical in circuit arrangement and it will be understood that similar equipment is associated with each of the different blocks of .the railway system, and that in the interests of clarity, only equipment 5 is shown in detail.

While any suitable system of signals may be employed in equipments l, 5, and 6, I have shown a plurality of lamps which indicate different track conditions when selectively lighted. For example, when the lamp R is energized, the occupied condition of the block B or danger is indicated.l When'the lamp Y is energized, the occupied condition of the adjacent block in the direction of traic or caution is indicated and when the lamp G is energized .for clear or safe the condition of both of the above mentioned blocks is indicated. I have indicated at I a power supply circuit which is `normally energized from a source 8 and which may extend throughout the railway system. Energy from the supply circuit 'I is supplied through transformers 9, I0, and II to signaling equipments I, 5, and 6, respectively.

Track circuit equipment for blocks A, B, and C is indicated conventionally at I2, I3 and I4. Any of the standard types of track circuits may be used and since the track circuit forms no part of this invention the circuit is illustrated diagrammatically by a rectangle.` It will be understood that the track circuit supplies a direct current to the signal equipment only when the block with which itl is associated is in an unoccupied condition.

Referring to signaling equipment 5 which I have illustrated in detail in the drawing, it will be noted that the lamp circuits-of signal lamps R, Y and G are connected in parallel to the secondary winding of transformer IIJ. In order se-- lectively to control the flow of current through `the different lamp circuits two saturable reactors I5 and I6 are provided in series in the caution lamp circuit and the clear" lamp circuit respec' tively. Saturable reactor I5 is provided with a direct current winding II which determines the degree of saturation of reactor I5 and hence the flow of current through the alternating current winding I8. When direct current is flowing through winding Il, alternating current from supply line l will flow through winding I8. Saturable reactor I6 is provided with a direct current winding I9 and an alternating current winding 20, and operates in a'manner similar to that of reactor I5 to control the flow of current through the clear lamp circuit. Since vinding I1 of reactor I5 is connected to track circuit I3 of block B, it will be understood that reactor I5 will remain saturated and hence will permit current flow through winding I8 as long as block B remains in an unoccupied condition. Similarly, since winding I9 is connected to track circuit I4 of block C, reactor I6 will remain saturated and hence will permit current flow through winding 20 as long as block C remains in an unoccupied condition.

A novel means is provided for turning off the danger lamp R when current is owing through the caution lamp circuit and for turning oil? the caution lamp Y when current is flowing through the clear lamp circuit A transformer 2I having its primary connected in series in the caution lamp circuit and its secondary connected in shunt to danger lamp R supplies a current of like magnitude but opposite phase to that normally flowing through danger lamp R when current is flowing through the caution lamp circuit. A transformer 22 having its primary connected in series in the clear lamp circuit and its secondary connected in shunt to caution lamp Y supplies a current of like magnitude but opposite phase to that normally flowing through caution lamp Y when current is flowing through the clear lamp circuit.

In order to prevent current ow in the clear" lamp circuit when no current is flowing in the caution lamp circuit a saturable reactor 23 is provided having its alternating current winding 24 connected in series in the clear lamp circuit. The direct current winding 25 of reactor 23 is connected through a suitable rectifying device 26 to an auto-transformer 21 connected in series in the caution lamp circuit. Consequently, reactor 23 will be saturatedonly when current is flowing through the caution lamp circuit. Similarly, a reactor 28 is provided having its alternating current winding 29 connected in series in the caution lamp circuit and its direct current winding connected through a rectifying device 30 to an auto-transformer 3| connected in series in the danger lamp circuit.

A ballast reactor 32 may be provided in series in the danger lamp circuit if desired. In order to provide the same voltage drop across danger lampR as is applied across caution lamp Y and clear lamp G, one side of the danger lamp circuit is connected to an intermediate point 33 on the secondary of transformer III, rather than to the end point.

The normal operation of my device is as follows: When both blocks B and C are in an unoccupied condition, current fiows through all three of the parallel lamp circuits but only the clear lamp G will be energized since current supplied from transformers 2l and 22 causes deenergization of danger lamp R and caution` lamp Y respectively. If block C be occupied and block B unoccupied, reactor' I6 will be unsaturated and no current will :dow through the clear lamp circuit. Since current flows through the caution lamp circuit, caution lamp Y will be energized but danger lamp R will be deenergized because of current supplied thereto from transformer 2|. If block B be occupied and block C unoccupied reactor I5 will not be saturated and hence no current will ow through the caution lamp circuit. Since no current ows in the caution lamp circuitno direct current will be supplied from rectifying device 26 to direct current winding 26 of reactor 23 hence no current will ow through the clear lamp circuit. Therefore, under these circumstances danger lamp R will be energized and caution lamp Y and clear lamp G will be deenergized. v

In order to improve the reliability of performance under various types of failure. a novel construction has been adopted for saturable reactors I5 and I6. The alternating current winding in the usual form of saturable reactor consists of two coils which are normally. operated in parallel. A short circuit of either one of these coils is a possible type of failure which may result in a dangerous indication. Reactors I5 and I6 preferably are constructed in such a. way that the alternating current winding is made up of a plurality of separate coils. For example, alternating current winding I8 of reactor I5 is made up of a plurality of separate coils Ita, I8b, and I8c connected in series and so arranged that a short circuit of any one coil will not interrupt the normal operation of the circuit. In order to improve the reactance ratio that is available in control reactors I5 and I6 I prefer to construct these reactors with tertiary windings 34 and 35 respectively which have a plurality of condensers 36-and 31 connected in shunt across them.

Case 1.-Green light on' Result Possible failure R Y G Reactor 16 Normal operation Oli Oil On (a) Open d-c winding Oil On 011 (b) Short d-c winding OIT On Off (c) Short any section 0I a-c wind s Off Oil 0n d) Open an section of a-c winding Oi! 0n 0I! e; Short ei er condenser Oil Off On (j Open either condenser Oil Dim Off Reactor15 Normal operation Off Od 0n (ag Open d-c winding On Off Oil (b Short d-c winding On Off Oil c) Short any section a-c winding. Oil! Oi! On d) Open any section a-c winding. On Oil Ol! (e) Short either condenser 0I! OII On (f) Open either condenser Oif Oil 0n Reactor 23 l Normal operation Oil Ofi On (a) Shortd-c winding Oif On 011 (b) Open d-c winding Ofi 0n On c) Short either section ac winding Off 011 0n 2d) Open either section a-c winding Oil.' On Off Reactor 28 Normal operation Oil Off On (a) Short d-c winding On Oft 0d' gb) Open d-c winding Oft Od c) Short either section a-c coil. Ofi 0n (d) Open either section a-c coil 0I! Ofi Ballast reactor 32 Normal operation Od Oif 0n (a) Short any section 0d 01T 0n (b) Open any section Oi! O 0I! Transformer 22 Normal operation OII Off On (a) Short top side Oli Oli On (b Open top side--- Ot! 0n 0I! c) Short lower side. Off Dim On d) Open lower side l.. Ot! On Ofi Transformer 21 Normal o ration Oil Off O (a) Short top side... pe O 0H Og b Open top side--. 0n OIT Otl.' c Short lower side. Ofi 0n (d) Open lower side 0 Oil 0d Case II.-Yellow light on i Result Possible failure Il Y G Reactor 16 Normal operation Oil On Oil Cu) Short d-c winding. Oil On Oil (b) Open d-c winding Oil On Oil c) Shortany section a Oil On Oil d) Open any section a-c. Oil 0n Oil (e) Open either condenser.- Oil On Oil (f) Short either condenser Oil 0n Ofi Reactor 15 Normal operation Oil On Oil (a) Short d-c winding On Oil Ofi (b) Open d-c winding. 0n Oil Oil (c) Short any section a-c- Oil On Oil (d) Open any section a-c On Oil Oil (e) Open either condenser. Oil Ou Oil (I) Short either condenser Oil On Oil Reactor 23 Normal operation Oil 0n Oil (o) Short either a-c coil Oil On Oil (b) Open either a-c coil Oil On Oil (c) Short d-c coil Oil On Oil (d) Open d-c coil Oil Onl Oil Reactor 28 Normal operation Oil On Oil (a) Short d`c coil On Oil Oil (b) Open d-c coil On Oil Ofl (c) Short any section a-c coil. Oil On Oil (d) Open any section a-c coil On Oil Oil Transformer 22 Normal operation Oil On Oil (a) Short top side Oil Oil Oil zb) Open top Side. Dini On Oil c) Short lower sid Dim Oil (d) Openlower side 0n Oil Transformer 21 Normal operation Oil On Oil (a) Short top side Oil On Oil (b) Open top side..- On Dim Oil (c) Short bottom side. Dim 0n Oil (d) Open bottom side On Oil Oil Ballast reactor 32 Normal operation Oil On Oil (a) Short any section Orl On Oil (b) Open any section Od Oil Oli Case IIL-Red light on O Result Possible failure R Y O Reactor 16 Normal operation On Oil Oil (a) Short d-c coil On Oil Oil (b) Open d-ccoll..- On Oil Oil (c) Short any a-c co On Oil Oil d) Open any a-c coil. On Oil Oil e Short either condenser On Oil Oil Openeitber condenser. On Oil Oil Reactor l5 l Normal operation On Oil Oil (a) Short d-c coil On Oil Oil (bg Open d-c coil.. On Oil Oil (c Short any a-c coil On Oil Oil (d) Open any a-c coil On Oil Oil (e Short either condenser.. On Oil Oil Open either condenser On Oil Oil Reactor 23 Normal operation On Oil Oil (a) Short d-c coil. On Oil Oil Oil Oil Oil Oil Oil Oil Reactor 28 Normal operation On Oil Oil (a) Short d-c side On Oil Oil (b) Open d-c side.... Oil Oil (c) Short any a-c coil Oil Oil (d) Open any a-c coil l Oil Oil Ballast reactor 32 Normal operation On Oil Oil (a) Short any a-c coil On Oil Oil (b) Open any a-c coil Oil Oil Oil Transformer 22 Normal operation On Oil Oil (a) Open top side Oil Oil (b) Short top side.1. Oil Oil (c) Open bottom side.. Oil Oil (d) Short bottom side On Oil Oil` Transformer 21 Normal operation` On Oil Oil (a) Open top side 0n Oil Oil (b) Short top side Oil Oil Oil Open bottom side.. On Oil Oil Short bottom side Dim Oil Oil It will readily be observed from the above tables that under any possible failure the indication will be either the same as under normal operation or will be more restrictive to traffic.

While I have shown a particular embodiment of my invention, it will of course be understood that I do not wish to be limited thereto since many modifications may `be made both in the circuit arrangement and the instrumentalities employed and I contemplate by the appended claims to cover all such modifications as fall within the true spirit and scope of my invention.

What I claim as new and desire to secure by Letters Patent of the United States, is:-

1. The combination comprising. a plurality of signals, means for de-energizng one of said signals by current supplied from the energizing circuit of a second of said signals, and additional means for de-energizing said second signal when the normal energizing circuit of said first signal is broken.

2. The combination comprising a source of current, a plurality of electrically operable signals connected in parallel to said source, means for selectively energizing said signals, a saturable reactor in one of 'said circuits, and means operable in response to a flow of current in asceond one of said circuits for saturating said reactor. l

3. In a railway signal circuit, the combination comprising a source of alternating current, a.

plurality of signals, including clear, caution, and

danger signals having their energizing circuits connected in parallel to said source, means for selectively de-energlzing said caution signal circuit and said clear signal circuit, means operative when current is ilowng through said caution signal circuit for supplying a currentto said danger signal which is of like magnitude and opposite phase to that normally flowing through the energizing circuit of said danger signal, and means operative When current is flowing through said clear signal circuit for supplying a lcurrent to said caution signal which is of like magnitude and opposite phase to that normally flowing through the energizing circuit of said caution 4. In a railway signal circuit, the combination comprising a source of alternating current, a plurality of signal lamps, including clear, caution, and danger lamps connected in parallel circuits to said source, means for selectively der energizing said caution lamp circuit andr said clear lamp circuit, means operative when current is owing through said caution lamp circuit for supplying aA current through said danger lamp which is of like magnitude and opposite phase to that normally flowing through said danger lamp,

Ameans Qperativewhen current is flowing through said clear lamp circuit lor supplying a current through said caution lamp which is of like magnitude and opposite phase to that normally flowing through said caution lamp, and means for when current is flowing through said cautioni signal circuit for`superlrnposing a current on the through said clear signal circuit for superimposing a current on the energizing circuit of said caution signal which is of like magnitude but opposite phase to the normal energizing circuit of said caution signal.

6. In a railway signal circuit, the combination comprising a source of current, a plurality of signals including clear, caution, and danger signals connected in parallel circuits to said source, means for selectively energizing said signals according to track conditions, a saturable reactor in said clear signal circuit, means in said caution signal circuit for saturating said reactor when current is owing through said caution signal circuit, a second saturable reactor in said caution signal circuit, and means in said danger signal circuit for saturating said second reactor when current is flowing through said danger signal circuit.

7. In a railway signal circuit, the combination comprising a source of alternating current, a -plurality of signal lamps, including clear, caution, and danger lamps connected in parallel circuits to said source, means for -selectively deenergizing said caution lamp circuit and 'said clear lamp circuit, means operative when current is flowing through said caution lamp' circuit for supplying a current through saidh danger lamp which is of like magnitude and opposite phase to that normally owing through said danger lamp, means operative when current is flowing through said clear lamp circuit for supplying a current through said caution lamp which is of like magnitude and opposite phase to that normally flowing through said caution lamp, a saturable reactor in said clear lamp circuit, means in said caution lamp circuit for saturating said reactor when current is flowing through said caution lampcircuit, and means in said danger lamp circuit for saturating said second reactor when current is flowing through said danger lamp circuit.

8. In a railway block signal system, the combination comprising a section of railway track divided into three blocks, a source of alternating current, a plurality of signal lamps in each block including clear, caution, and danger lamps connected in parallel circuits to said source', means operative when current is owing through the caution lamp circuit of a block for supplying current through the danger lamp of the same block which is of like magnitude andV opposite phase to that normally owing through said danger lamp, means operative when current is flowing through the clear lamp circuit` of a block for supplying a current through the caution lamp circuit of the same block of like magnitude and opposite phase to that normally flowing through .said caution lamp, saturable reactors Vin said caution lamp circuits and said clear lamp circuits, means in said second block for controlling the degree of saturation of the saturable reactor in the clear lamp circuit of said second block,

, in parallel circuits to said source, means including a plurality of saturable control reactors for selectively energizing said lamps according to track conditions, a saturable safety reactor in said clear lamp circuit, means in said caution lamp circuit for saturating said safety reactor when current is flowing through said caution lamp circuit, a second saturable safety reactor in said cautionv lamp circuit, and means in said danger lamp circuit for saturating said second safety reactor when current is flowing through said danger lamp circuit, each of said reactors being provided with a sectionalized alternating current Winding thereby to prevent a layer to layer short circuit or a turn to turn short circuit from affecting the normal operation of the signalling system.

l0. The combination comprising a sourcel of current, a plurality of signals connected in parallel thereto, means for .eenergizing one of said signals `in response to current in the circuit of another of said signals and means comprising a saturable reactor in said circuit for controlling the signal therein in accordance with the current in the circuit of said one signal.

11. The combination comprising a source of current, a plurality of circuits connected in` parallel to said source, a signal in each of said circuits, means for deenergizing the signal in one of said circuits by the current in another of said circuits and means comprising a saturable reactor in said other circuit for deenergizing the signal therein in response to an opening of said one circuit.

12. The combination comprising a source of current, a plurality of circuits connected in parallel to said source, a signal in each of said circuits, saturable reactor means in said circuits for selectively energizing said signals, means responsive to the current in one of said circuits for deenergizing the signal in another of said circuits and means including a saturable reactor in said one circuit and controlled by the current in said other circuit for deenergizing the signal in said one circuit.

13. The combination comprising a source of current, a plurality of circuits connected in parallel to said source,- a signal in each of said circuits, means including a saturable reactor in each ofsaid circuits for selectively energizing said signals, means responsive to the current in one of said circuits for deenergizing the signal in another of said circuits, a second saturable reactor in' said onecircuit for lcontrolling the signal therein, a reactor in said other circuit and means -for supplying saturating current therefrom to said second saturating reactor. 

